Many industries utilize silicone tubing for the delivery and removal of fluids because silicone tubing is non-toxic, flexible, thermally stable, has low chemical reactivity, and can be produced in a variety of sizes when compared with tubing made from other materials. For example, silicone tubing may be used in a variety of industries such as the medical industry, pharmaceutical industry, food delivery, and the like. However, silicone tubing is limited due to its undesirable permeation rates attributed to air ingress in the fluid path and evaporation of solutions in the fluid path. As such, thermoplastic elastomers are desirable for their permeation rates, low coefficient of friction, and low tack, however, thermoplastic elastomers are not ideal for processing or performance.
Composite tubing is a multiple layer tubing system. Composite tubing is desirable with a silicone material as one of the layers; however, composite tubing is typically formed by heat curing silicone materials at an elevated temperature. For instance, temperatures in excess of at least 150° C., such as at least 160° C., such as at least 170° C., or even up to or greater than 200° C., are used for the heat cure. Due to the elevated temperature needed for heat cure, silicone materials have typically been commercially used with high melt temperature substrates for multiple layer articles. These multiple layer articles are typically expensive since they are limited to high melt temperature substrates. Unfortunately, adhesion between dissimilar materials such as silicone materials and thermoplastic materials can also be problematic.
Accordingly, an improved composite tube and method to form a multiple layer composite tube are desired.